Service and meter-test system and associated apparatus



B. D. HORTON.

SERVICE AND METER TEST SYSTEM AND ASSOCIATED APPARATUS.

APPLICATION FILED MAR, 28. 1919.

Patented Apr. 27 1920.

8 SHEETS-SHEET 1.

B. D. HORTON.

SERVICE AND METER TEST SYSTEM AND ASSOCIATED APPARATUS.

APPLIQATIQN. FILED MAR, 28- 1919.

1,338, 1 0 Patentefii A r. 27, 1920s.

8 SHEETS-SHEET 2.

B. D. HORTON.

SERVICE AND METER TEST SYSTEM AND ASSOCIATED APPARATUS.

APPLICATION FILED MAR. 28, 1919.

1,338,180. Patented Apr. 27, 1920,.

V 8 sHEETS-SHEET 3.

67 Li /g6.

1 1 II. Tul

Arrwwvzy B. D. HORTQN.

SERVICE AND METER TEST SYSTEM AND ASSOCIATED APPARATUS.

APPLICATION FiLED MAR, 28, I919.

Patmte'd Apr. 27, 1920.

8 SHEETSSHEET 4.

INVENTOR Byaon, D. /7 M ATIORNEY B. D. HORTON.

SERVICE AND METER TEST SYSTEM AND ASSOCIATED APPARATUS- APPLICATIONFILED MAR. 28. 1919.

"1 ili al lW INVENTOR Byson D. h

B. D, HORTON.

SERVICE AND METER TEST SYSTEM AND ASSOCIATED APPARATUS.

APPLICATION FILED MAR, 28. I919.

Patented Apr. 27, 1920.

a SHEETS-SHEET s.

INVENTOR son .0. flan .Mxt I ATTORNEY v 9 III I 215 L owwvoall F T B. D.HORTON.

SERVICE AND METER TEST SYSTEM AND ASSOCIATED APPARATUS.

APPLICATION FILED MAR,28,1919- 1,338, 180. Patented Apr. 27, 1920.

'8 SHEETS-SHEET 7- HIM "'m glHllmi ENVENTOR Byson .0. orfon B. D.HORTON.

SERVICE AND METER TEST SYSTEM. AND ASSOCIATED APPARATUS.

APPLICATION ELLE!) mmza, 1919.

1,338,180. Patented Apr. 27, 1920-.

8 SHEETS-SHEET 8.

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ATTORN EY UNITED STATES PATENT OFFICE.

' 1,338,180. co ma To all'whbht it may concern:

Be it known that I, BRY'soN a citizen of the United States, residing atDetroit, in the county of Wayne and State .of Michigan, have inventedcertain new and useful Improvements in Service and Meter-Test Systemsand Associated Appara tus, of which the following is a full,

- clear, and concise description.

This invention relates. to impr ved circuits-and apparatus for serviceand meter test systems and associated apparatus, and

more-particularly to improved circuit cont -01 mg apparatus andimprovedmeans for in rjconnec ting and associating said apparatus toobtain sim lified and more eflicient' swi'tching, and a equate togetherwith Fproper protection for said apparatus and -wiring to preventunauthorized tampering therewith.

In so far as concerns common subject matter, this application is acontinuation of my co-pending applications, Serial No. 762,773 filedApril 22, 1913, andentitled Electrical switches and test devices, andSerial No. 879,481 filed December 29, 1914, entitled Electrical switchesThe principal requisites of a service and test'meter system reside inthe production "of means wherebythe service circuit can be quicklyswitched from the service condltion to the meter test condition. In thisswitchin operation, according to the best commercial practice, theservice meter is disconnected from the load circuit and this switchingshould be accomplished without interrupting the connection between theservice .andload circuits. When the normal service circuit is thusconverted to the test condition, with the service meter disconnectedfrom the load, thepower applied to the consumer is not measured. It istherefore very essential that the circuit be restored to the originalservice condition as soon as the meter has been tested, Likewise it isimportant to i'nclose the apparatus and the interconnecting wiring usedfor the service and test switching circuits, in an adequate protectivehousing whereby the probability of tampering with the apparatus andwiring by unauthorized individuals, will be reduced to a minimum,

thereby reducing the possibility of theft.

' Specification of Letters Patent.

-BR YSON D. HORTON, OF DETROIT, MICHIGAN.

AND METER-TEST SYSTEM AND ASSOCIATED APPARATUS.

Patented Apr. 2'7, 19%.

in part of applications Serial No. 762,773, filed.April 22, 1913, andSerial No. 879,481, filed December 29, 1914. This application filedMarch 28, 1919. Serial No. 285,856.

- testing circuit and associatedapparatus in- D. HORTON,-

ing means interposed between the serviceswitch and the load, the saidswitching means being adapted to carry and properly interrupt thecomplete load current.

A further object of the invention consists in the production of improvedmeans for inclosing service and meter test apparatus and interconnectingwiring, in a protective housing, inaccessible to unauthorizedindividuals, and with which means are provided externally of saidhousing and always accessible, for controlling the connection betweenthe service and load cir- ,cuits.

An additional object of the invention resides in the production ofimproved means whereby the inclosure must be opened to conduct a metertest and improved means which will necessitate the switching of the testmeter into the normal service circuit from the test circuit before thesaid protective inclosure for said circuits and apparatus can. beclosed.

Further objects of the invention will become apparant from the followingdescription andthe appended claims.

For the purposes of description, several Which Figure 1 illustrates infront elevation the service switch and testing device inclosure,together with a meter, the meter and the service switch andtestingdeviceinclosure being combined in a protective structure for the associatedapparatus and interconnecting wiring;

Fig. 2 is a front elevation of the inclosure illustrated in Fig. 1, withthe cover removed, and shows the service switch and meter-testingswitching apparatus positioned within said inclosure, and the servicecircuit indicatcd diagrammatically;

Fig. 3 is a view similar to Fig. 2 with the test meter circuitsdiagrammatically included;

Fig. 4 is a section taken on the plane indicated by the line 4-4 of Fig.2, looking in the direction of the arrows, of the meter test apparatusinclosure;

Fig. 5 is a bottom plan view of the test plug by means of which the testconnections are made;

Fig. 6 is a side view of the test plug, showing the positioning keys'employed to facilitate the centering of the plug and assure properinterconnection between the plug. and its cooperating fixed testing apparatus;

Fig. 7 is a bottom plan view of the test plug showing the operativeposition of the keys and the grooved barrier;

Fig. 8 is a detail of the test plug, taken on the plane represented bythe line 88 of Fig. 7, looking in the direction of the arrows;

Fig. 9 is an illustration in perspective of a two-wire service switchinclosure, comprising the service switch and the necessary apparatus formaking the testing connections, the apparatus as shown in this figurebeing in service condition;

Fig. 10 is an illustration ,in perspective taken from the opposite endof the inclosure to that shown in Fig. 9, showing the apparatus thereillustrated in test condition;

Fig. 1]. is a view, partly in section, looking down at the upper end ofthe meter load disconnecting'switch, with the switch in test conditionas shown in Fig. 10.

Fig. 12 is a wiring diagram of a two- .wire circuit of the apparatusshown in Figs. 9 and 10, in service condition;

Fig. 13 is a similar wiring diagram with the apparatus in testcondition;

Fig. 14 is a plan view of a protective inclosure for a meter, a serviceswitch and testing apparatus, and illustrates the apparatus necessarywith a three-wire circuit for testing with the two current coils of themeter in series across the negative and positiveline terminals of athree-wire circuit, the apparatus as shown in the diagram beingpositioned in service condition;

Fig. 15 is a wiring diagram showing the apparatus illustrated in Fig. 14switched to the test condition;

Fig. 16 is a plan view of a protective switch inclosure for a threewirecircuit equipped with service switch and meter testing apparatus, thetesting apparatus being arranged to test the meter coils in series fromone side of the line to the neutral wire, the apparatus as shown in thisfigure being connected in the service condition;

Fig. 17 is a section taken on the plane represented by the line 17-17 ofFig. 16, looking in the direction of the arrows; and

Fig 18 is a wiring diagram showing the apparatus illustrated in Fig. 16in test condition.

Referring now in detail to the embodiment illustrated in Figs. 1 to 4inclusive, it will be noted that the housing or inclosure 20, carries aninsulating base 21, and is fitted with a cover 23 hinged at 24. Mountedupon the base 21 are the service line terminals 25 and 26, to which areattached the service conductors 27 and 28. Theline terminals 25 and 26also carry theswiteh contact clips 29 and 30; and positioned on theopposite end of the insulating-base 21 are the cooperating switchcontact clips 30 and 31 respectively. The switch contact clips 29 and30' respectively and 30 and 31 respectively, are bridged by the movableportion of a switching mechanism operated by the handle 32, whichmechanism is supported on the hinged cover- 23 of the receptacle, andconsists of conventional switch blades and protecting fuses 33' and 34,shown in broken lines in Figs. 2 and 3.

Mounted directly beneath the service switch inclosure 20 is theinclosure33 carrying the testing apparatus. This apparatus consists of aninsulating base'34 mounted on the bottom of the housing 33, saidinsulating base 34 being equipped with the terminal clip contacts 35 and36, to which are secured the contact bars 37 and 38, which are.car-

ried through an opening interconnecting the housings 20 and 33, to theservice switch contact clip terminals 30 and 31. Secured to the lowerend of the insulating block 34 are the terminal clip contacts 39 and 40,the clip contacts 39 and 40,together with the switch blade 41,constituting what may be called either a load controlling or preferablya meter load disconnecting switch. The

blade 41 is pivoted to the clip contact 39 at 42 and cooperates withsuitable clip contacts in the terminal clip contact 40. Connected to thehousing 33 by a suitable meter adapter 43 is any type of an electricmeter 44 of usual and well known construction; The meter is electricallyconnected with the testing switch by means of the wires 45, 46 and 47,these wires all being carried through the meter adapter 43 andcompletely inclosed in'the protective inclosure.

The consumers load is connected to the conductors 48 and 49 and iscarried in to the inclosure through a suitable opening in the wall ofthe inclosure, with w ich is preferably interconnected a conduit such as50. A suitable cover or lid 51 is fitted over the inclosure 33 andlocked and sealed in place as hereinafter to be described.

In the embodiment of the invention illustrated in Figs. 1, 2 and 3, theservice switch and meter test inclosing housing are shown as individualand separate parts, but ohviously these parts could readily be com binedinto one inclosure, capable of receiving all the apparatus associatedwith the service circuit as well.as the switching cir- With theapparatus positioned as indicated in Fig. 2, the current will be fed to'the consumer through the service switch and the meter over a circuitwhich may be traced as 'follows: from service lead 27 to terminal 25,through the combined fuse and switch (blade 33' to switch contact 30,and then i by way of the conductor .strip 37 to the I terminal 35,thence byway of conductor 45 the coil 52 of the service meterandconductor46 to terminal 39, through the 15 meter "load disconnectingswitch to terminal 40 and to conductor 49 of the load circuit, throughthe load circuit, and back by way of load conductor 48 to terminal 36,conductor strip 38, terminal 31, combined fuse and switch blade 34', andterminal 26 to the other service line conductor 28.

In order to make connection with the test contact clips 35, 36, 39 and40 of the meter test apparatus, a test plug illustrated in Figs. 5, 6, 7and 8, equipped with two depending angular-faced keys, or centeringportions, 53 and 54, is provided. These are attached to the base of theplug 55 and are positioned slightly off center as shown in Figs. 5 and7. Cocperating with these positioning mem ers or keys is a suitablebarrier 56, rigid y secured to the insulating base 34 of the testswitch, said barrier being fitted with laterally extending wings wherebyangular grooves or key-ways 57 for the reception of the positioningmembers 53' and 54-are provided.

Due to the off-centering of the keys orprojecting members 54 and 53, andthe necessity of alining the test switch contact clips 57, 58, 59 and60, with the clip contacts 39, 40', 35 and 36 respectively, on theinsulating base, it is impossible to insert the test plug knife bladecontacts 57 to 60 inclusive into the test switch contact clips in awrong position.

'In the normal operative condition of the units illustrated in Figs. 1,2 and 3, the cover of the service switch is retained closed by means ofa lug and thumb nut connection, which consists of the lug 61, integrallywith the cover 23, a screw 62 carried by the body of the inclosure, anda nut 63 having a collar 64 cotiperating with the screw 62 and the lug61 to hold the cover in its closed position. The thumb nut 62 isprovided with an eye or perforation, and a like perforation is providedfor the lug 61 through which is threaded a sealing-wire 65, the ends ofwhich are joined by any suitable seal such as 66.

A similar construction 67 is provided for holding the cover 51 of thetest inclosure 33 in closed position, and a similar sealing means 68 isemployed for sealing both the the load circuit.

meter cover and the test switch cover 51 in closed position for thepurpose of preventing tampering with the connection without detection.

' When it is desired to test the service meter 44 the cover 51 of thetest inclosure 33 is removed and the test plug illustrated in Figs. 5,6, 7 and 8 is connected in position with its cotiperating test contactclips. The t test clips 57 to 60 inclusive of the test plug are mountedon the insulating base 55, the base 55 being equipped with a suitableoperating handle 67. The switch contacts 57 to 60 are preferably madeL-shaped, each having an in-turned end 68, 69, 70 and 71. Ends 68, 7 0and 71 areprovided with binding posts such as 72, fitted withcoiiperating binding nuts 73. Connected to the clips 57, 59 and 60 bymeans of the binding nuts such as 73, are the test conductors 74, 75 and76 respectively.

'With the cover 51 of the test in'closure removed, the first operationin making the test is to insert the test plug with its associated testclips 57, 58, 59 and 60,. in position in the coiiperating test contactclips 39, 40, 35 and 36 respectively. When the test plug is thus placedin position the meter is bypassed by means of the conductor 77interconnecting the terminals 58 and 59 of the test plug.

The next operation in making the test is to open the meter loaddisconnecting switch 41 which disconnects the service meter from \Vhenthese operations have been performed the current or power from theservice circuit is fed directly to the load circuit without passingthrough the service meter, said meter being disconnected from the loadcircuit, and the test circuit for calibrating the service meter isestablished and comprises a suitable test meter 78, and an artificialload 79, with the proper interconnections therebetween connected tonected from the load circuit is performed without in anyway operatingthe service switch and its appurtenant apparatus, and consequently thetest plug and its associated connections, as well as the load circuit,are protected by the main service switch and fuses 33 and 34.

With the apparatus in this condition, the flow of current to the loadcircuitmay now be traced on the wiring illustrated in Fig. 3. From theservice conductor 27 through the service switch to the interconnectingconductor 37, to the contact terminal 35, thence through the bypassconductor 77 to conductor 49 of the load circuit, through the load, backover conductor 48 of the load circuit to terminal 36, and thence throughthe interi the service switch, the conductor 37 and contact 35,throughthe coil 52 of the meter to contact 39 of the load switch andthence through the blade of the load switch 41 and the terminal 40 ofthe load switch to the load conductor 49, having been bypassed, may beopened by the meter load discon necting switch 41 at, the contact clip40,-

thereby disconnecting the meter at this point from the 'load circuit.

The service meter 44 can now be readily tested Without interfering withthe supply of current to the consumer and this test circuit may betraced as follows: from the service conductor 27 through (pie side ofthe service switch, the conductor 37, and thence over wire 45 throughthe series coil 52 of the service meter to terminal 39, thence over wire74 to the series coil 80 of the calibrating meter, wire 81 to the testload 7 9, through the test load and thence by' means of wire 76 to thecontact 60 of the test plug, the terminal 36 and conductor 38, to theother side of the service switch and service wire 28.

In this meter test or calibrating circuit just outlined, the series coilof the service meter is connected in series with the series coil of thecalibrating meter, and in series with an artificial load across thepotential of the service circuit. The shunt coil of the service meter isconnected across the line from the contact 35 to the contact 36. Theshunt coil of thecalibrating meter is connected across the samecontacts, the current flowing from contact 35 through lead 75, the coil,leads 82 and 7 6 to the clip 36.

With these conditions established the meter can be properlycalibrated'without interference of any kind with the supply of power tothe consumer. The load controlling switch or meter load disconnectingswitch 41 is arranged to prevent the closing of the housing or inclosure38 for the meter test switching apparatus, unless the said meter loaddisconnecting switch is in its normal position, in which condition thepower supplied to the consumer passes through the series coil of theservice meter. This requirement is desirable so as to necessitate theswitching of the connections to such condition, after testing the meter,that the meter will be included in the service circuit.

To accomplish this purpose the blade 41 of the meter loaddisconnectingswitch is fitted with a handle 83 of insulating material, as clearlyindicated in Fig. 4, the said handle being so positioned that when themeter load disconnecting switch is operated to its extreme open positionthe curved forward apertured portion of said insulating handle will reston the top edge of the inclosing wall of the housing 33, With the switchhandle in this position it will be evident that the cover 51 cannot beplaced upon said inclosure. In order to place said cover on theinclosure the blade of the meter load disconnecting switch must beswitched to its closed position, and in order to insure that the bladewill be moved to its extreme closed position the upwardly extendingportion of the handle 83 is of such a size and is so designed that saidupper portion of the handle will just clear the cover 51, when the saidcover is locked in place. Consequently if at any time the switch blade41 is operated so that the blade does not properly contact with itscooperating switch contacts, due to an incomplete operation of theswitch blade, the said blade will be driven home to its closed positionby the cover 51 when it is placed in position because of theintercontacting surfaces of the top of the handle 83 and the insidesurface of the cover 51. Consequently when the tests are completed andthe switch plug is removed the housing or inclosure cannot be put in itsnormal closed condition without switching the service meter intoitsproper position in the load circuit.

In this connection it should be noted that the meter load disconnectingswitch, with its blade 41 and cooperating contacts 39 and 40, isconnected in the load circuit so that the circuit to the consumer may beinterrupted by this switch. The construction of this switch is such thatit will properly carry all the current flowing in the load circuit andwill likewise properly function to interrupt the current flowing in saidcircuit. The meter load disconnecting switch may consequently be used ifdesired in place of the service switch in the circuit here shown forinterrupting the How of current from the service circuit to the loadcircuit.

Referring now to Figs. 9, 10, 11, 12, and 13, which show the preferredembodiment of a two-wire service circuit fitted with a protectiveinclosure, carrying the service switch and the necessary testingapparatus, it will be noted that inthis preferred embodiment all theapparatus utilized incontrolling the service circuit as well as theapparatus which is used for test purposes, are inclosed in a singleprotective housing 84. The housing, as clearly illustrated inperspective in Figs. 9 and 10, is fitted with an opening, through whichprojects an operating handle 85 by means of which the actuator member 86of the service switch 87 can be operated from the exterior of thehousing. The housing 84 consequently serves to completely inclose andprotect against tampering or unwarranted molestation the apparatus andcircuits inclosed within the housing, and at the same time control ofpower from the load circuit to the service circuit is readily obtainedbythe exterior handle 85 which controls the operation of the serviceswitch. The housing 84 is fitted on one end with a slid-able end-plate88, fitted with suitable wiring or conductor admitting means, in theparticular instance conduit knock-outs 89, and at the other end with aslidable,'removable meter hood 90, adapted to receive a meter inprotective union with the switch inclosure 84. Whenthe meter is fittedinto the meter adapter 90, and the cover 91 of the inclosure locked inplace, the apparatus and wiring within the housing whichintercon nectsthe-meters, the test switching apparatus and the service switch, will beinclosed in a protective housing which cannot be entered into except byauthorized individuals.

Obviously any type of end-plate 88 or meter hood 90 canbe used inconnection with the switch inclosure 84.

The perspective'shown in Fig. 9 is taken with the box turned through.180 degrees from that shown in Fig. 10, in order to clearly show theapparatus used for switching and testing mounted within the inclosure. a

Fig. 9 illustrates the condition of the apparatus in the switchinclosure when in service condition. Under these conditions the servicewires enter through a suitable conduit, and are connected to the serviceswitch, from which point they are wired through the fuses and by way ofthe meter load disconnecting switch 92 and the meter, not

' shown in the structure, to the load circuit.

nected to the side 102 of the service switch] 87. The switch blade 95 ofthe meter load disconnecting switch consists of a sector shaped orquadrantal plate 103 which carries at its upper periphery a normalflange 104.- The blade 95 is also fitted with an operating handle 105and with a perforation 106 and a like perforation similarly disposed atthe other side of the blade. The contact clips 94 and 93 are alsoperforated as illustrated at 107-and108. Theperforations in the blade 95coiiperate with theperforations 107 and 108 in the contact clips 93 and94 respectively; one of the perforations in the blade being in alinementwith the perforations in the contact clips 93 and 94 respectively whenthe said blade is actuated 'to either its extreme upper or its extremelower: operating position. The alined'perforations serve as a means forsealing or looking the meter load disconnectin switch ineither of itsoperating positions, the sealing being accomplished in any of the usualmethods employed, as, for example, by passing a wire through the alinedperforations and sealing the ends thereof. Connected to the fuse sockets101 and 109 are the conducting strips 110 and 111. Each of these strips1S fitted with test pins or terminals 112 and 113. The meter loaddisconnecting-switch, the service switch and the associated switches andbars are all mounted upon an insulating base 114, secured to the base115 of the housing by means of screws such as 116.

Thecircuit connections of the apparatus in normal service condition,when the apparatus is positioned as indicated in Fig. 9, can now betraced on Fig. 12- as follows: from service lead 117 through one side ofthe service-switch to .fuse 101, through conductor 110 to the contact100, thence by way of wire 118 through the series coil 119 of theservice meter, conductor 120, to terminal 98 of the meter loaddisconnecting switch, through the blade 95 of said switch, terminal 97,and out through the load circuit, thence back through conductor 121 tothe link 122 of the meter, over conductor 123 to the contacting bar 111,and finally by way of fuse 109- and the other blade of the serviceswitch to the other service lead 124. In the circuit just traced themeter load circuit which extends from one side of the load to one sideof the service circuit may be traced from the service wire 117 throughone blade of the service switch, fuse 101, conductor 110, terminal 100,conductor 118, series coil 119 of the service meter, to terminal 98 ofthe meter load disconnecting switch, through the operating blade 95 ofthe switch and contact 97 thereof to one side of the load circuit.

It will be observed, therefore, that the series coil of the servicemeter is connected from one side of the service circuit to the loadcircuit through the movable blade of the meter load disconnectingswitch, and conse uently that if said movable blade 95 is shifted to itsalternate position, breaking the contact between the blade and thespring contact clip 94, the meter will be disconnected from the loadcircuit.

The operating blade 95 of meter load disconnecting switch, is sopositioned and so designed with respect to its cocperating switchcontact clips 93 and 94 that said blade will make contact with thecontact clips toward which it is moving before it the meter andsupplying power to the customer from the service leads, direct throughcuit.

the service switch and fuses to the load cir- Due to thismake-before-break connection of the meter load disconnecting switch, thecustomers service circuit is not interrupted when the switch fromservice condition to the test condition is made, the sequence of thisoperation being controlled by the switch whereby the meter will bebypassed before it is disconnected from the load circuit.

The circuit conditions when the meter is to be tested are illustrated inFig. 10, which shows the apparatus condition, and Fig. 13 which shows awiring diagram of the circuit conditions. When -a test is to beconducted, the test plugs 124, 125 and 126 are placed in position on thetest terminals 99, 112 and 113 respectively. These test plugs areinterconnected with the desired calibrating meter and artificial loadcircuit as indicated in the circuit diagram in Fig. 13. The test plugsare constructed with an insulating sleeve 127 within which is positionedthe conductor 128, arranged for cooperation with the test pins 99, 112and 113. The conductor 128 is connected to suitable wires connected withthe testing apparatus. When the test plugs 124, 125 and 126 have beenplaced in position, the meter load disconnecting switch is operated toits testing position as indicated in Figs. 10 and 13.

It will be observed that the test plug 124, which is fitted on the testterminal 99, is equipped with a projecting annular collar 129 at itslower end. This collar prevents insertion of this test plug on itscooperating test pin 99 when'the meter load disconnect ing switch hasbeen operated to the testing position, and likewise prevents removal ofthis testing plug from its cooperating test ing pin unless the meterload disconnecting switch is operated to the service position because ofthe interpositioning of the flange 104 in the path of the collar 129 asclearly By means of this interaction between the annular projectingcollar 129 of the test plug and the flange 104 of the meter loaddisconnecting switch it is impossible after a test has been made, toremove the test plug ture whereby it is impossible for a? carelessoperator to remove his testing apparatus, close up the switch inclosureand' leave the circuits in condition whereby power will be supplied tothe customer with the meter out of the service circuit. Likewise, due tothe length of the plugs 124, 125and 126, it is impossible to close theswitch housing or inclosure until the said plugs have been removed fromtheir cooperating testing pins, and inasmuch as the plug 124 cannot beremoved until the meter load disconnecting switch has been moved to theservice condition, it is impossible for an operator to close theprotective housing for the sery ice switch and test switching apparatusuntil the service meter is connected in proper circuit relationship withthe load and service circuits.

T heconnections for the service and testing conditions as indicated inthe circuit diagram on Fig. 13, for the condition of the apparatus asshown in Fig. 10, may now be traced as follows: The power is supplied tothe consumer from service lead 117, through one side of the serviceswitch, the fuse 101, the conductor 110, the blade 95 of the meter loaddisconnecting switch, terminal 97, to one side of the load circuit, andthence through the load, back over conductor 121, meter link 122,conductor 123, conductor 111, fuse 109, and through the other blade ofthe service switch to the other side of the service circuit 124.

The flow of current through the circuit just traced is through themovable blade of the meter load disconnecting switch which bypassed themeter when it was shifted from its service to its test condition, andthen disconnected the meter from the load circuit as hereinbeforedescribed.

The testing circuit may be traced as follows: from the-service lead 117through one blade of the switch, to the fuse 101, conductor 110, contactterminal 100, wire 118, series coil 119 of-the service meter, conductor120, terminal 98, test plug 124, conductor 130, artificial load 131,series coil 132 of the calibrating meter, conductor 133, to the testplug 126, test pin 113, conductor 111, fuse 109, the otherblade of theservice switch and thence to the other service conductor 124. Thiscalibrating or meter test circuit just traced contains the service andcalibrating meters in series together with an artificial load, wherebythe service meter can be checked against the calibrating meter. Thepotential coil of the test meter is connected directly across the linefrom conductor 110 by means of test plug 125, conductor 134, through thepotential coil of the meter 135, conductor 136, and test plug 126, toconduccompletely inclose all the apparatus and the wiring containedwithin the housing in a protective inclosure to prevent tamperingtherewith. In the case of a three wire chcuit.

cuit the meter load disconnecting switch shown at 92 in Fig. 9 isduplicated on both the positive and negative sides of the servicecircuit, and the movable blade 95 of the switch is interconnected by aninsulating handle 141 by means of which the blades 95 of the twoswitches-are operated in unison.

Vith the apparatus shown in this figure, when a test is to be made, aplug with a collar similar to 124 isinserted on the fixed test contactsor terminals 142 and 143.

Likewise a plug of the type illustrated at 126 is placed on the fixedtest contact terminal 144 and a plug of the type shown at 125 isinserted on the fixed test contact terminal 145' Plugs 125 and 126 aresimilar in construction, the only difierence being that plug 126 is madesomewhat heavier inasmuch as it carries the test current, whereas plug125 is merely a potential plug.

The arrangement of apparatus in the three-wire circuit is very similarto that used in connection with the two-wire circuit and consequently itis deemed necessary, in connection with this apparatus, to merely tracethe circuit for the service condition as indicated by the superimposedwiring in the box inclosure in Fig. 14, and for the test condition asindicated in the wire diagram in Fig. 15. r

The service circuit as illustrated inthe wiring superimposed upon theapparatus in the plan view of Fig. 14 may be traced from the positiveservice lead 146 to the service switch contact 147, through the blade148 of the service switch, the fuse 149, the conductor 150, connector151, conductor .152,- service meter coil 153, conductor 154,

connector 155, blade 95 of the load switch and connector 156 to one sideof the load circuit, and thence through the load to the neutral wire157, connector 158, fuse 159,

switch blade 160, connector 161, and back to the neutral lead 162 of theservice cir- The connections from the other side of the service circuitthrough the meter and load to the neutral are identical to those justtraced, using the apparatus on the opposite side of insulating base162'.

"When it is desired to make a test with a three-wire circuit of the typehere shown, in which test the two series coils of the meterare connectedacrossthe positive and negative of the service wires, test plugs likeplug 124 are inserted on the test terminals or pins 142 and 143, andtest plugs like plug 125 are inserted on the test erminals 144 and 145.When the test terminals are thus inserted the operating arm 141 of themeter load disconnecting switch is moved to its top position whereby themeter is first bypassed and then disconnected from the load circuit oneither side of the line as hereinbefore described in connection with atwo-wire circuit. p

ikewise when the meter load dlsconnecting switch is thus operatedtheplugs in serted on the testpins 142'and 143 cannot be removed fromthe said test pins until the meter test disconnecting switch is returnedto the lower position, in which the I meter coils are connected inserieswith the load circuit. The purposes and functions of thiscoiiperation between the plugs and the meter load disconnecting switchhave all been described heretofore in connection with the two wirecircuit.

The circuit in testing condition may now be traced on the diagram Fig.15 as follows: from the positive service wire 146 to two service metercoils are connected inseries with the coil of the calibratin meter,together with an artificial loa across the outside wires or fullpotential of and the service circuit. The test plug connected to thefixed-test contacttermmal 144is connected by means of wire 177 to oneside of the potential coil of the'calibrating meter, the other side ofthis coil of the calibrating meter being connected by means of theconductor 178 and the test plug to the fixed test contact pin 145, tothe other or negative side of the service potential.

As the service meter is bypassed during the test, the service circuitmay be traced as follows: from the positive side of the service circuit146 to terminal. 147, service switch.

blade 148, fuse 149, conductor 150, by means of movable switch blade 95of the meter load disconnecting switch and terminal 156 to one side ofthe load circuit, thr6ugh the load circuit and by means of the neutralwire to the terminal 158, the fuse 179 and the switch blade 160 totheneutral. wire of the service circuit 179. The other side of the servicecircuit during test condition is identical to that just traced, usingthe apparatus and'wiring on the opposite side of the insulating base162.

\Vhen it is desired in a three wire circu1t to test the two coils of the.service meter across from one side of the line to the neutral, theapparatus and circuit for testing must be somewhat modified, thismodification consisting essentially in disconnecting.

one of the meter coilsfrom the service circuit as well as the loadcircuit, the modification being illustratedin Figs. 16 and 18. In thiscase the meter load disconnecting switch operating handle 180 isconnected to three switching elements 95, whereby all of these elementswill be operated simultaneously when themeter load disconnecting switchisoperated. For testing purposes in this case five plugs are used whichare connected to the fixed test contact terminals 181, 182 and 183, 184,and terminal 185 hidden under the operating handle 180. The generalarrangement of parts within the protective inclosure is the same in thiscase as in the disclosure shown in Fig. 14, the service switch beingoperable from the exterior of the housing.

However, when it is desired to make this character of test it isnecessary to guard I against circuit complications in the nature shortcircuits when the testing apparatus 1s connected in circuit. For thisreason the 85 apparatus shown in Fig. 16 is fitted with fool proofguards to prevent these circuit complications, in addition to the guardprovided in all the circuits whereby it is necessary to return the meterload disconnecting switch to theposition in which the service meter isconnected in theload circuit before all the portable testing apparatuscan be removed. The circuit complications referred to and the sequenceof operation of the apparatus shown in F i 16 will be readily apparentfrom the foliiwing detailed tracing and description of the circuits.

Thecircuit in the service condition is indicated by the wiringsuperimposed upon the apparatus shown in Fig. 16. This circuit may betraced as follows: from the positive service wire 186 to the contact187, the switch blade 188, fuse 189, the-conductor bar 190, conductorblade 95, connector terminal 191, conductor 192, meter coil 193,conductor 194, through the switch blade 95' to terminal 195, to the loadconductor 196 and thence back through the load to the 200, serviceswitch blade 201, fuse 202 and conductor 203 to terminal 203', thencesby way of conductor 204 through coil 205 of the service meter andconductor 206 to terminal 207, and then by way of switch blade 95 andterminal 218 to the load wire 219, through the load circuit and back byway of neutral load wire 197, fuse 213, the service switch blade 213 andthe terminal 180 to the neutral service lead 198.

Vhen it is desired to test, a plug with a collar is inserted on fixedtest contact terminal 184, which test plug cannot be inserted on saidtest pin after the meter load disconnecting switch has been operatedbecause of the interposition of the flange 104 of the blade 95 ashereinbefore described. A potential plug like plug 125 can also beinserted on the test pin 183 and a plug with a collar on the test pin182 before the meter load disconnecting switch is operated, butpreferably the last two plugs are connected in place after theswitch hasbeen operated when the plugs connected to test ins 181 and 185 areconnected in circuit he plug that is connected to pin 181 is fitted witha collar like plug 124 and due to this collar the plug cannot be,connected to pin 181 because of the interposition of the flange 104 ofthe-blade 95 in the path of the collar of the plug, as clearly shown inFig. 16. When normal service position the actuating insulating arm 180thereof, rests directly over the test pin 185 (see Figs.v 16 and 17) andthereby prevents the connection to this pin of a test plug like 126until the switch is operated to its upper position. Therefore in View ofthe inherent design of the apparatus it is impossible to connect thetest plug to pin 184 after the meter load disconnecting switch has beenoperated to its upper position, and it is impossible to remove the plugfrom this test pin until after said switch is operated to its lowerposition. This plug therefore acts as the fool proof guard whereby allof the portable testing apparatus cannot be removed from circuit nor theapparatus housing closed until the service meter is switched from thetest circuit into the load-circuit. Also it is impossible to connect thetest plugs to pins 181 and 185 interpositioning ofthe flange 104 of theswitch 95, the said flange having a square end like that shown at 181 inFig. 9, whereby the end of the flange will strike on the collar of theplug, andthe operating arm or,

handle 180 of the switch will strike against i which will prevent thereturn of the switch until this plug has been removed. The pre cautionsprovided for preventing the insertion of the test plugs on the test pins181 and 185 and the necessity for removing both of these plugs beforethe switch can be returned to its lower position are essential toprevent the circuit complications hereinbefore referred to and describedhereinafter in the detailed tracing of the testing circuit.

If it be assumed now that the meter load disconnecting switchillustrated in the normal service condition in Fig. 16 has been operatedto its upper or test position, and

the testing plugs placed in the respective positions in the order orsequence hereinbefore described, then the testing circuit illustrateddiagrammatically in Fig. 18 will have been established, which circuitmay now be traced asfollows: from the neutral side of the. servicecircuit through the service switch to the fuse 213, thence by way of thetest terminal 182, a test plug, conductor 212, and another-test plug totest terminal 181, and then by way of terminal 191, conductor 192,service meter coil 193 and conductor 194 to test terminal 185, fromwhere the circuit can be followed through a test plug conductor 211, theartificial load 210, the series coil 209 of the test meter, theconductor 208, a test plug, test terminal 184:, contact terminal 207,and conductor 206,

through the other coil 205 of the service meter and thence by way ofconductor 204, terminal 203, conductor 203, the fuse 202, the serviceswitch blade 201 and terminal 200 to the negative side 214 of theservice circuit.

The circuit of the potential coil of the meter for the test circuit maybe traced from the fixed test contact terminal 182, test plug andconductor 215, through the potential coil to conductor 216, the testplug and contact terminal 183 to the negative side of the line. 1

It will be obserwed from the circuit just traced that the service metercoil 193 is connected in test circuit by means oftest plugs connected totest pins 181 and 185, both ends of the coil 193 of the service meterbeing entirely disconnected by the operation of the meter loaddisconnecting switch, one end from the load circuit and the other endfrom the service circuit. This complete disconnection of this coil ofthe meter from the load and service circuit makes it possible, by meansof the test plugs and test pins provided, to connect the meter in anytype of test circuit. Consequently whenever it is necessary for thepurpose of making tests with other circuits to completely disconnect themeter coil from the load and service circuits, a meter loaddisconnecting switch having two blades for each coil of the metersimilar to that shown in Fig. 16 must be use In the test circuit justtraced it will also be noted that the 'calibrating'coil as well as thetwo coils of the' service meter are all connected in series with anartificial load between one side of the circuit and neutral.

The circuit complications which are. avoided because the test plug whichtakes the fixed test contact terminal 185,- cannot be placed upon thesaid contact until the load meter disconnecting switch is thrown to thetesting position and vice versa, will now be described. This precautionserves to prevent the inclusion of the test circuit across the negativeand positive side of the line, or full potential, which would occur ifthe test plug were connectible to test pin 185 before tie loaddisconnecting switch were operated. Inasmuch as the calibrating circuitis adapted for calibrating on onehalf the voltage maintained across theline between negative and positive, the calibrating apparatus would beinjured by this higher voltage and consequently it is essential that aguard be provided to prevent the placing of the plugs on test pin 185and connecting up the testing apparatus until the meter loaddisconnecting switch is operated. The positioning of test terminal 185under the operating handle 180 of the meter load disconnecting switchconsequently serves as a fool proof feature whereby the testingapparatus cannot be damaged by an excessive current or potential.

Likewise as hereinbefore stated the collared test plug cannot be placedon test pin 181 until the meter load disconnecting switch has beenoperated to bypass the meter, and vice versa. This precaution isnecessary to prevent the connection of the test conductor 212 and itsassociated plugs to their respective test pins 181 and 182, whichconnection would short circuit the neutral and positive leads over acircuit traceable from the positive service conductor through the fuse189, the conductor strip 190, blade 95 of the meter load disconnectingswitch and thence by way of the test pin 181, its associated test plug,conductor 212, the other test plug, and fuse 213 to the neutral sideofthe service circuit. Obviousl when the meter load disconnecting switciis first operated before test pin 181 and its cooperating test plug areconnected this short circuit just traced is interrupted by the switchblade 95 at terminal 181. Also since the cooperation of the projectingcollar on the plug associated with test pin 181 and the flange 104 ofthe blade 95 prevents the return of the meter load disconnecting switchto service condition until the said test plug has been removed, andtheoperating arm 180 of the meter load disconnecting switch cannot bereturned 'to normal service condition until the test plug connected totest terminal 185 has been removed, the aforesaid circuit complicationscannot be established by a premature operation of the switch. Also sincethe test plug connected to test terminal 184 cannot be removed until theswitch has been returned to normal service condition, all the portabletest apparalib cannot be removed and hence the apparatus housing cannotbe closed until the meter load disconnecting switch has been operated toconnect the meter coils in the load lead 212 has a plug with a collarattached to either end. This precaution is taken so that no matter whatend of the test lead 212 is connected to test terminal 182, the plugattached to the other end will be equipped with the necessary guard to)revent the completion of the short circuit etween the positive andneutral service wires. Obviously the collar on the plug when used withthe test pin 182 serves no useful function.

It therefore follows that the meter load disconnecting switch serves toinsure the proper sequence of operation in setting up the test circuitand in disconnecting the test apparatus, whereby no circuit difficultieswill bev encountered and whereby the service circuit will be leftproperly connected.

During the testing condition the meter coils are bypassed by means ofthe meter load disconnecting switch and the power is supplied to theconsumer over a circuit that may be traced from the one side of theservice circuit 186 through the terminal 187 to switch blade 188, fuse189, conductor" strip 190. movable blade 95 of the meter loaddisconnecting swi ch, the terminal 195, and thence to the load circuit,through the load and back to the neutral side of the service circuit198. The connections for the other side of the circuit may be tracedfrom the negative service lead 214 through terminal 200 to switch blade201, fuse 202,

conductor strip 203, movable blade 95 of the meter load disconnectingswitch and terminal 218 to the load conductor 219, through the load andthence back to the neutral side of the service circuit 198.

It will be evident that in all the circuits hereinbefore described,whether testing or service circuits, the load, as well as the testingapparatus, is always protected by the service switch and the fuses, thefuses and service switch always being included in series in thesecircuits.

Likewise, the service controlling apparatus, as well as the metertesting apparatus and the meter, with their interconnections between theservice circuit and the load circuit, are all inclosed in a protectivehousing, casing or inclosure, which prevents unauthorized tampering withany of this apparatus or any of the wiring, while at the circuit. Itwill be noted that the test 1 same time the service switch is soarranged that it can be readily operated from the exterior of saidcasing or housing, thereby giving control of the service circuit fromthe exterior of the housing. Inasmuch as all of the apparatus isinclosed within the housing, testing of the apparatus can beaccomplished only when the housing or casing is opened, and in thatmanner access to the testing switches, terminals and apparatus as wellas wiring becomes impossible to those not entitled or authorized to haveaccess thereto.

The cooperation of the parts, apparatus and circuits as described in theforegoing consequently results in a device in which the service switchcan be controlled by any and all individuals, and the control of theapparatus and wiring for meter testing and any other complicatedelectrical functions, which require experts, can be accomplished onlyupon opening the cover, and they are therefore inaccessible to anyoneexcept experts authorized to make the meter tests or any other changesdesirable in the circuit connections. Further, the test appliances areall provided with proper guards and tool proof features, whereby it isimpossible to make the wrong connections and also impossible to removeall the portable testing apparatus or close the apparatus housingwithout first returning the service meter into the load circuit.

In the descriptions hereinbefore outlined, the tests have all been madein connection with an artificial load. It will be obvious to anyoneskilled in the art, however, that with the apparatus described any ofthe authorized standard meter testing circuits can be established andthe standard meter tests made. llhus, for example, there are fourregular standardized methods of testing meters:

First, test with an artificial or a resistance load using centralstation power, which is used for either alternating or di rect current.This is the type of test which has been illustrated in the foregoingdescriptions.

Second, there is what is known as the phantom load test, which isadaptable for alternating current only.

Third, the customers load test, in which the customers load is used inplace of the artificial load, and

Fourth, test with separate sources, wherein the service potential issupplied to the shunt coils of the service and test meters and in whichthe series coils are energized from a low voltage storage batterythrough a variable resistance.

It will be evident, in view of the fact that the meter is disconnectedby the load disconnecting switch from the load circuit in severalembodiments of the apparatus hereinbefore described, and disconnectedfrom both the load and service circuits in one embodiment, that any ofthese circuits can be readily set up by anyone skilled in the art.

Obviously this invention is not limited to the specific embodimentthereof herein illustrated and described but is capable of manyvariations and other applications within its spirit and scope, aspointed out in the following claims.

What is claimed is:

.1. In a device of'the character described, in combination, a serviceswitch, a protective inclosure therefor having a cover, means locatedexterior of said inclosure for operating said switch, a load circuit inelectrical connection with said switch, a meter adapted to measure thepower delivered to said load circuit, and meter test ing meansindependent of said service switch for calibrating said meter andaccessible only upon .the opening of said cover.

2. In a device of the character described, in combination, a serviceswitch, a protective inclosure therefor, means located exterior of saidinclosure for operating said switch, a load circuit in electricalconnection with said switch, a meter adapted to measure the powerdelivered to said load .circuit, a calibrating circuit and metertestswitch, a meter adapted to measure the power delivered to said loadcircuit, and meter testing means independent of said service switch forcalibrating said meter, ac

cessible only upon the opening of said cover, and comprising means forbypassing 'the load current around the meter and then disconnecting themeter from the load circuit.

4. In combination, a service circuit, including ajservice switch, aprotective housing for said switch, a load, a meter load circuit, a loadcurrent by-pass, a meter calibrating circuit, means operable from theexterior of the inclosure to open and close said service switch, meansoperable only when the saidhousing is open to interrupt'the meter loadcircuit and close the meter calibrating I circuit, said by-pass insuringan uninterrupted flow of current when the meter load circuit is opened.

5. In combination, a service circuit including a service switch, aprotective housing for said switch, a load, a meter load circuit, a loadcurrent by-pa'ss, a meter calibratcircuit,

ing circuit, means operable from the outside of said housing to open andclose said service switch, a meter included in said meter loadconductors interconnecting said meter and service switch, a meteradapter intermediate said meter and said housing completely inclosingsaidconductors, and means operable only when said housing is opened tointerrupt the meter load circuit and close the meter calibratingcircuit, the flow of current to the load circuit being uninterruptedwhen the meter load circuit is opened.

6. In a system of the character described, a service switch, aprotective inclosure for said switch, means positioned outside ofsaidinclosure for operating said switch, a load circuit in electricalconnection with said switch, a calibrating circuit, a meter coilinterposed between the'said load circuit and said switch, and meansindependent of said service switch positioned in said inclosure andaccessible only when the inclosure is opened for'switching the metercoil from the load circuit into said calibrating circuit.

7. In a device of the character described, in combination, a serviceswitch, a protective inclosure therefor, means located exterior of saidinclosure for operating said switch, a load circuit in electricalconnection with said switch, a meter adapted to measure the powerdelivered to said load circuit, means operable to switch said meter intoa testing circuit, the said means being positioned in said inclosure andaccessible only when the inclosure is opened, and means necessitatingthe switching of said meter into the load circuit before said inclosurecan be closed.

8. In a device of the character described, a service switch, aprotective inclosure for. said switch, means positioned outside of saidin-- closure for operating said switch, a load circult 1n electrlcalconnection wlth said switch,

a calibrating circuit, a meter interposed between the said circuit andsaid switch to measure the power delivered to said load circuit, meanspositioned. in said inclosure and accessible only when the inclosure isopened for switching the meter from the load circuit whereby the flow ofcurrent from the service switch to said load circuit will beuninterrupted during said switching operation.

9. A device of'the character described, comprising, in combination, aservice switch, a protective inclosure for said switch, means positionedoutside of said inclosure for operating said switch, a load circuit inelectrical connection with said switch, a meter adapted to measure thepower delivered to said load circuit, means for disconnecting said meterfrom said load circuit, the said into said calibrating circuit, andmeans means being operable only when the said inclosure is opened, andtesting means adapted to calibrate said meter when thus disconnected.

, trical connection with said switch, a meter adapted to measure thepower delivered to said load circuit, means for disconnecting said meterfrom said load circuit, the said means being operable only when the saidinclosure is opened, testing means adapted to calibrate said meter whenthusdisconnected, and means necessitatin theinclusion of the meterin theload circuifiiefore the said testing means can be removed. I

11. In combination, a service circuit, including a service switch, aprotective housing for said switch, a load, a meter load circuit, ameter calibrating circuit, means op erable from the exterior of theinclosure to open and close said service switch, means operable onlywhen the said .inclosure is opened to interrupt the meter load circuitand close the meter calibrating circuit, andmeans requiring there-closing of the meter load circuit to permit the closing of saidhousing.

12. A device of the character described, comprising, in combination, aservice switch, a protective inclosure for said. switch, meanspositioned outside of said inclosure for operating said switch, a loadcircuit in electrical connection with said switch, a meter adapted tomeasure the power delivered tov said load circuit, means fordisconnecting said meter from said load circuit, the said means beingoperable only when the said inclosure is opened, testing means adaptedto calibrate said meter when this disconnected, means necessitating thereestablishment of normal circuit connections through the meter to theload circuit before the said testing means can be removed from the saidtesting -circuit, and means associated with said testing means requiringthe removal of said testing means before the closed.

13. In combination, a service-circuit including a service switch, aprotective inclosure for said switch, a load, a meter load circuit, ameter calibrating circuit, means operable from the exterior of theinclosure to open and close said service switch, and means operable onlywhen the said inclosure is opened to interrupt the meter load circuitand establish the meter calibrating circuit.

14. In combination, a service circuit including a service switch, 'aprotective inclosure for said switch, a load, a meter load circuit, ameter calibrating circuit, means operable from the exterior of theinclosure to open and close said service switch, a meter loadcontrolling switch included in protective inclosure can be .metercalibrating circuit, means operable from the exterior of the inclosureto open and close said service switch, a meter load controlling switchincluded in said meter load circuit, a test terminal and cord 00-operating with said switch, said terminal and cord being included insaid meter calibrating circuit, and means whereby said terminal and cordcan be disconnected from said calibrating circuit only after the said,switch has been operated to establish the meter load circuit.

16. In combination, a service circuit including' a service switch, aprotective inclosure for said switch, means operable from the exteriorof the inclosure to open and close said service switch, a load, a meterload circuit, including a meter load controlling switch, a metercalibrating circuit, including a test terminal cooperative with saidcontrolling switch, and means whereby said terminalcan be connected ordisconnected only when said meter load controlling switch is in apre-determined position.

17 In a device of the character described, in combination, an ironcladinclosure including a cover, a service switch mounted therein, means foroperating said service switch located exterior of said inclosure, a loadcircuit, a meter ada ted to measure the power delivered to sai loadcircuit, and

a meter load disconnecting switch operable terior of said inclosure foroperating said switch, a load circuit in electrical connection with saidswitch, a meter adapted to measure the power delivered to said loadcircuit, and cooperating-switch and testing means whereby said meter canbe switched from the load circuit and tested only when '120saidinclosure is opened and the said inclosure can thereafter be closedonly after the meter is re-connected to the load circuit.

19. In a device-of the characterdescribed, in'combination, a serviceswitch, a protective inclosure therefor, means located exterior of saidinclosure for operating said switch, a load circuit in electricalconnection with said switch, a meteradapted to

